Process for extracting and purifying bitumen



Nov. 9, 1948. v. R. LCGAN 7 2,453,633

PROCESS FOR EXTRACTING AND PURIFYING BITUMEN Filed om. 14, 1946 I 3O 28 I 28::

22mm ig 1 Condensed I -Quivent J v --|6 3e I VICTOR LOGAN V I slliviifrlgefild I INVE/VTUR 4; Fig.2 I

Patented Nov. 9,, 194 8 PROCESS FOR EXTRACTING AND 1 PURIFYING BITUMEN w Victor R rI logan, Brownsville, Ky. Application October 14, 1946, Serial No. 703,233. l

tially pure asphaltum, from the aggregate, of finely crushed or comminuted rock, sand, and the like earthen matter in which it naturally occurs, one example of these natural deposits being found near Brownsville, Kentucky. Heretofore,

attempts have been madeto extract and purify bitumen from its aggregate simply by flowing a solvent for the bitumen directly through a body of crushed rockasphalt and subsequently boiling off the solvent, and while small amounts have been so obtained, the major portion of the bitumen collected in definite, impenetrable lay ers or hardpan in the aggregate. The material forming the hardpan Was not only lost to the desired product, but the hardpan blocked further flow of the solvent therepast, so that once the hardpan formed, further attempts to continue the process were useless. Further, it was to a process and appaa Fig. 2 is a diagram generally at 2, is providedwitha removable, top

4 having a solvent inlet 6 coupled at 8 with a solvent supplypipe I 0.

Chamber 2, havinga cylindrical sidelwall l2 and a perforated bottom I4, rests at the top of a cylindrical reservoir it which, inturn, has

suitable structural supports (not shown) and an outlet pipe 18, it being understood,that chamber 2 is removable, by conventional but not illustrated lifting ringsor the like, from reservoir I6 sothat an aggregate of crushed rock asphalt 2.0 may be loaded in or dumped from the chamber.

The operation of the apparatus thus far described is as follows: after chamber 2 has been filled With the aggregate 20 of crushed rock asphalt, atsolvent' is introduced throughinlet found that if a confined body of rock asphalt were saturated with a solvent, not one but several hardpans formed in Well defined, vertically spaced horizontal strata. The object here is to provide an apparatus and process for flowing solvent through a mass of rock asphalt in such manner that the tendency towards stratification is substantially overcome and so that whatever hardpan starts to form is both rendered harmless and automatically eliminated at its very inception. i h I In the physical embodiment of the invention, it is proposed to provide a chamber for receiving an undistributed mass of natural but, crushed rock asphalt, and a fluid system for flowing solvent into the chamber at its top and for egress of the solvent and dissolved bitumen at the chamber bottom, the chamber thus forming a,

primary vertical passage for the fiuid. The particular inventive feature concerns the provision of a plurality of relatively short secondary vertical passages disposed at spaced vertical and angular intervals around the exterior of the chamber, the length and vertical placement of the secondary passages being such as to bridge at least part of the vertical section which, but for them would, in the process, soon would be occupied entirely by hardpan.

These and other objects will be apparent from the following specification and drawings, in Which: 1

Fig. 1 is an elevation, broken awayin parts, illustrating the extracting chamber; and,.

6. The preferred solvent is casing headgasoline enriched with a relativfil small percentage of a, higher boilingqsolvent, such ,as one gallon of any one of a number of commercial hydrocarbon paint thinners to each fifty gallons of gasoline (assuming in this example that chamber 2 contains 850 pounds of finely crushed Kentucky rock asphalt). The solvent passes downwardly through aggregate 20 to pick up, and carry with it the pure bitumen fromthe aggregate, through perforated bottom l4, toreservoir I6. This actioncontinues for a short time until layers of hardpan 22 form'in the aggregate 20, these hardpans, inrthe absence of the inventive apparatus, would block further flow, of the solvent and thus terminate the process 3 One characteristic of the hardpan, formed ,of starshaped granules of crushed rock, or sand closely compacted with bitumen, is that it is extremely hard andcrusty on top, as indicated at 24,- and that it tapers off sjomewhatin consistency towards the bottom of the layer. Another characteristic is that it tendsfto form in several distinctwhorizontal strata Withsubstantially consistent vertical spacing,,evidently proportional to the bitumen content of the, aggregate which, near Brownsville, Kentucky, averages about6 per cent by weight. Whilethe sand between the formed hardpans is then relatively light in bitumen content, attempts to force solvent through the sands and hardpans only im pacts the crust of the first hardpan encountered.

In accordance with the invention, anfumber of secondary, passages 26 :are arranged around ENT OF illustrating fluid flow in the system utilizing the extracting chamber. Referring now to the drawing, in which;lil;e reference numerals denote similar elements, the extracting and purifying chamber, indicated chamber 2, these passages being defined by C- shaped pipes 28 having their ends connected into openings 30 inside wall I2.

It should be noted particularly that vertically spaced sets of passages 26 are arranged with the the chamber to the side of, but near the bottom of a hardpan.

The function of secondary passages 26 is as follows: as the solvent flows downwardly through aggregate 20 in chamber 2, which maybe considered the primary passage, and dissolves bitumen from the sands, the solution thereby becomes thicker and tends to stratify to formhardpans,

22. In the example .now described, however, hardpans never do form completely since, as they "start to form, the resistance todownward flow of the solvent is increased'so that,-at the top of an incipient hardpan, the relatively clear solvent ".flows off to the side, into the upper ends of pipes 28and through the pipe-defined secondary passages 26 from which it is introduced back into the lower portion of the thickening strata. Upon introduction of the solvent into the lower portion "of the wouldbe hardpan, the-strata of the thickened' solution of bitumen'an'd solvent are underout bythe'relatively clear solvent flowing around from the top so that the strata, in effect, destroy themselves beforethey encrust' and form complete hardpan. The action of the secondary passages 26 may be "observed by forming some of pipes 28 as glass gauges. In'the course of a typical run, cloudy liquid, i. e., thesolvent and bitumen, may be observed flowing "downwardly through the several 1 gauges until, after a few minutes, the liquid clarifies, thereby indicating that the formation of the strata has commenced and that the solvent is flowing sidewise oh: the tops of the strata without picking up appreciable amounts of bitumen. After clear liquid'flows in the gauges 28a and "pipeS ZB for a few minutes. it again becomes occluded and flows less rapidly through the gauges, thereby denoting that the strata have been broken up and that the fluid flow is primarily downward through chamber 2.

may repeat many times in a typical five hour run. It has been observed that the strata to form closer together towards the bottom of the chamber, and that those strata near the bottom are of greater consistency. Accordingly, the several sets of pipes 28 should be closer spaced towards the bottom and there should be more pipes per set in the lower sets. To prescribe against an oc- 1 casional dephasing of the strata, a few long secondary pipes 28 and gauges 28a are disposed at @more. widely spaced vertical and horizontal inter- '-vals. If, desired, suitable-perforate guards may be placed over the upper-inner ends of pipes 28 to prevent clogging, although such clogging has I not yet been recognized as a problem.

:As'diagrammed in Fig; 2, the system further includes an outlet valve 34 in outlet pipe l8, a pipe 36 leadingfrom valve 34' to an evaporator 38, a .::gas heater All under evaporator 38, a vapor return pipe 42 leading from evaporator 38 to a condenser 44. andthe solvent inlet pipe from condenser 44 to', this topofchamber 2 so that a continuous process re-using the solvent may be carried on, 'saswill be apparent to thoseskilled in the art.

.r' Atzthexendof arun asrdescribed above, outlet These phases valve 34 may be closed and burner 40 left on sufficiently long to drive off most of the solvent through vapor return pipe 42, condenser 44, supply pipe l0, chamber 2, and collected in reservoir l6 after which burner 40 may be extinguished and substantially pure bitumen drawn from evaporator 38 through tap 48. With the ingredients as set forth however, about ZQgallons of highly useful bituminous paint comprising ;.about 40% bitu men and 60% solvent has been obtained by eliminating the solvent recovery step outlined above. If desired, the solvent remaining after a run in thecleansed sands may be recovered by known :methods. and apparatus.

While a successfully proved method and apparatus has been detailed for purposes of illustrating the'concept,.it.is to be understood that the invention is not limited to the specific apparatus and'steps disclosed, but is intended to embrace all modifications, substitutions, and equivalents within'the scope ofthe following claims.

- Iclaim'zb i -l. In the proce'ssfor extracting and purifying bitumen from anaggregate ofbitumen bearing crushed ore, the steps which compriseflowing a solvent' for the bitumen through the bodyof the aggregate until bitumen stratiiies' horizontally to form at least one hard pan in thebody, withdrawing solvent off the top of the hardpan, and introducing the withdrawn solvent into the hardpan near the bottom thereof. I

2; In the process for extracting and purifying bitumen from anaggregate of -bitumen-bearing ore, the stepswhich comprise flowing a solvent I for the bitumen generally vertically through a body of the aggregate until the bitumen stratifles to form at least one hardpan in the body, withdrawing solvent off the-top of the hardpan,in-

' troduoingthe' withdrawn solvent into the hardpan near the'bottom thereof until thehardpan isundercut, and flowing solvent generally vertically through the undercut hardpan.

3. In the process for extracting and purifying "bitumen froman aggregate of bitumen-bearing ore, the steps which"-compriseflowing a solvent for thebitumen generally downwardlythrough a body'of the aggregate until the bitumen stratifies to form a plurality of hardpans in the body,

' draining ofr said solvent from the top of thehardpans, and introducing the drained-off solvent into the lower portion of the hardpans near the bottom thereof. Y

4. In the process for extracting and purifying bitumen from an aggregate of bitumen-bearing ore, the steps which comprise flowing a solvent for the bitumen generally downwardly through a body of the aggregate untilthe bitumen stratifies to form at least one hardpan, collecting solvent on the top of the hardpan, draining off a portion of' the collected solvent, and introducingsaid portion generally laterally into the lower portion "offsaidhardpan" to undercut the hardpan until the solvent thereabove breaksdownwardly therethrough.

5. In'the process for .extractingand purifying bitumen from an aggregate of bitumen-bearing ore,.the steps-which comprise flowing a-solvent icy/the bitumen generally downwardly througha confined body of the aggregate until the bitumen forms a plurality of verticallyespaced horizontally extending hardpans, and simultaneously introducing said solvent substantially laterally into the 'hardpansnear the bottom-thereof to undercut the same; H

2,458,638 5 6 6. In the process for extracting and purifying REFERENCES CITED bltumen m an aggregate of bltllmen'beamg The following references are of .record in the ore, the steps WhlCh comprise flowing a solvent file of this patent: for the bitumen generally downwardly through a body of the aggregate until the bitumen stratifies 5 UNITED STATES PATENTS to form at least one hardpan, collecting solvent Number Name Date on the top of the hardpan, withdrawing a portion 5 5 Neiman Sept" 30 1834 of the collected solvent, and introducing the 5 3 Day Now 4 1924 withdrawn solvent into the hardpan near the bot- 2,112805 Bonotto Man 29, 1938 tom thereof until the hardpan is undercut and 10 2356336 Bonotto Apr 25, 1939 until the remaining solvent collected above the hardpan breaks downwardly therethrough. VICTOR R. LOGAN. 

